1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a semiconductor probe with a high resolution resistive tip and a method of fabricating the same, and more particularly, a semiconductor probe with a convex high-resolution tip, which has a diameter less than 100 nm, and a method of fabricating the semiconductor probe.
2. Description of the Related Art
As compact devices such as mobile communication terminals and electronic pocket notes become more popular, the demand for micro integrated nonvolatile recording media increases. It is not easy to miniaturize existing hard disks or to provide highly integrated flash memories. Therefore, information storage devices using scanning probe microscopy (SPM) have been studied as an alternative.
Probes are used in various SPM devices. For example, probes are used for a scanning tunneling microscope (STM) that detects current produced when a voltage is applied between a probe and a sample to reproduce information, an atomic force microscope (AFM) that uses an atomic force between a probe and a sample, a magnetic force microscope (MFM) that uses an interactive force between a magnetic field produced by a sample and a magnetized probe, a scanning near-field optical microscope (SNOM) that overcomes a resolution limitation due to the wavelength of visible light, and an electrostatic force microscope (EFM) that uses an electrostatic force between a sample and a probe.
In order to record and reproduce information at high speed and high density using the techniques of such SPM, a surface charge in a small area with a diameter of several tens of nanometers should be detected. Also, cantilevers should be arranged in an array to increase recording and reproduction speeds.
FIG. 1 is a cross-sectional view of a conventional cantilever 70 on which a resistive tip 30 is formed disclosed in International Patent Publication No. WO 03/096409. The resistive tip 30 is perpendicular to the cantilever 70 and has a resistive region 36 with a diameter of several tens of nanometers. The cantilever 70 can be fabricated in the form of an array.
Referring to FIG. 1, the resistive tip 30 of the semiconductor probe includes a body 38 doped with a first impurity, the resistive region 36 disposed at a peak of the tip 30 and lightly doped with a second impurity, and first and second semiconductor electrode regions 32 and 34 formed on inclined surfaces of the tip 30 and heavily doped with the second impurity. The resistive region 36 is disposed between ends of the first and second semiconductor electrode regions 32 and 34.
However, the conventional semiconductor probe with the resistive tip 30 has a disadvantage in that the first and second semiconductor electrode regions 32 and 34 formed on the inclined surfaces of the resistive tip 30 are excessively wet-etched during a process of forming the resistive tip 30, thereby reducing the areas of the heavily doped inclined surfaces. Conductive areas on the inclined surfaces are accordingly reduced, thereby degrading the spatial resolution of the resistive region 36. Also, the probe may be damaged when ions are implanted at a high energy of 300 keV in the fabricating process. Further, the probe may be damaged when a thermal diffusion process, that is, an annealing process, is performed at a temperature of 1000° C. for a long time, e.g., 12 hours. In addition, a thermal oxidation process is performed at a temperature of 1000° C. under an oxygen atmosphere for 30 to 40 minutes to sharpen the resistive tip 30.